1. Field of the Invention
The present invention relates to a process for producing an iron oxide used for a magnetic recording medium. More particularly, it relates to a process for producing a magnetite powder which imparts superior magnetic characteristics by reducing an iron oxide powder without sintering under high chemical stability even at high temperature.
2. Description of the Prior Arts
Magnetite powder has been used for a magnetic recording medium. Usually, the magnetite powder has been produced by reducing acicular goethite powder with hydrogen gas.
When the magnetite powder is used for the magnetic recording medium, excellent magnetic characteristics are required especially higher coercive force and intensity of magnetization are required.
Heretofore, in order to produce magnetite (Fe.sub.3 O.sub.4) by heating an iron oxide (Fe.sub.2 O.sub.3) in an inert gas, a high temperature such as higher than 1000.degree. C. has been required. When an iron oxide powder is used as the starting material, a sintering has been caused and a magnetite having desired magnetic characteristics could not be obtained.